If theology does not properly face its particular task regarding the truth claims of the Christian tradition, then it easily happens that the clergy of the church are the first to become insecure and evasive about the message they are supposed to preach. When they become doubtful about the truth of the gospel, they will tend to replace it by other ‘causes,’ and the believers will be disturbed, because they no longer get to hear in church what they rightfully expect to be taught here.
Replacing the Gospel with "other 'causes'" - sadly, that could end up being an epitaph for mainline denominations.
I agree with my clergy colleague who said that Pannenberg here gives both a reason and an antidote to church decline.
For more, check out Philip Clayton's obituary for Pannenberg. See also Michael Root's 2012 essay for First Things entitled "The Achievement of Wolfhart Pannenberg."